When ‘More’ Is a Breach: Overdesign and the Limits of Design Obligations in Modern Construction Contracts

Jovana Veletić

May 2026

The second prize winning entry in the Society of Construction Law’s Hudson Prize 2025, published in the SCL Journal: Spring 2026 

The paper examines the issue of overdesign and the possibility of being in breach of contract by exceeding an agreed limit. The paper looks at the traditional limits of liability under reasonable skill and care and why overdesign claims usually fail. It explores how outcome based obligations change the analytical lens, particularly where contracts impose measurable ceilings, drawing on existing case law and testing the issues against arbitration practice and investor led scrutiny of completed projects. The author concludes that overdesign claims are coherent where contractual limits are clear, but they remain evidentially demanding and will succeed only exceptionally.

Introduction – Why reasonable skill and care protects conservative design – When exceeding a limit becomes non-compliance – Case law on outcome obligations and loss – Worked example: when a ceiling is not an aspiration – Breach and proof: the counterfactual discipline – Overdesign allegations in arbitration: investor pressure and the hindsight trap –  Measuring excess: loss, differentials and proportionality – Will overdesign claims remain exceptional? – Conclusion

The author: Jovana Veletić is an Associate Director at Diales Technical

Text: 14 pages

Author
Jovana Veletić
Publication year
2026